ANTI-ENZYMES 57 



that the prcxkicts of their action on the tissues are the chief chemo- 

 tactic agents. 



The enzymes that are secreted into the gastro-intcstinal tract 

 seem to be chiefly destroyed, but part is ehminated in the feces, and 

 part that is absorbed apparently reappears in the urine in very small 

 quantities. *2 Pepsin, diastase, and rerinin all have been found in- nor- 

 mal urine; but trypsin is present chiefly as trypsinogen, especially 

 abundant after a meat diet.*^ Pepsin and rennin enter the urine as 

 the zjmiogens, in quantities in proportion to the amount in the stom- 

 ach, and are absent in gastric carcinoma (Fuld and Hirayama**). 

 During resolution of pneumonia, leucocytic protease may appear in 

 the urine (Bittorf*^). Ferments injected subcutaneously are said 

 seldom to be eliminated in any considerable amounts in the urine, 

 but Opie^^ has demonstrated the presence of lipase in the urine in 

 pancreatitis with fat necrosis, and Wago^^ found that injected trypsin 

 is excreted rapidly and abundantly. Hildebrandt was able to prove 

 that emulsin remained active for at least six hours after it was injected 

 into animals subcutaneously, by its splitting amj^gdahn which was then 

 injected, the CNH hberated by the cleavage of the amygdalin causing 

 death. 



Anti-enzymes 



Injection of enzymes into animals leads to the appearance of sub- 

 stance^ in the serum of the animals that antagonize the action of the 

 enzymes.*^ The principles involved are quite the same as in the im- 

 munization of animals against bacterial toxins or against foreign proteins. 

 This seems to have been first observed by Hildebrandt, and it has 

 been taken up extensively in recent years in the study of the problems of 

 immunity\ An interesting observation that was made rather early 

 in these studies was that normal blood-serum possesses a marked 

 resistance against the action of proteolytic enzymes, not being at all 

 digested by dilutions of enzymes that will rapidly digest a serum that 

 has been heated. This property seems to be shared by egg-white*^ 

 and by the tissues and organs of the body (Levene and Stookey^"). 

 The anti-enzyme action is easily destroyed by heat of about 70°, by 

 the action of dilute acids, and even by prolonged standing. It is 



^2 Falk and KoUeb, Zeit. klin. Med., 1909 (68), 156. 



"^v. Schoenborn, Zeit. f. Biol., 1910 (53), 386. 



" Berl. klin. Woch., 1910 (47), 1062. 



« Deut. Arch. kUn. Med., 1907 (91), 212. 



« Johns Hopkins Hosp. BuU., 1902 (13), 117. 



" Jour. Immunol., 1919 (4), 19. 



*8 According to Porter (Quart. Jour. Exper. Physiol., 1910 (3), 375) enzymes 

 in contact mth various membranes are inactivated, and substances appear which 

 are strongly inhibitive to the enzymes; it is possible that this effect depends 

 largely on zymoids, which unite -wath the substrate and deviate the enzymes. 



" Sugimoto, Arch. exp. Path., 1913 (74), 14. 



" Jour. Medical Research, 1903 (10), 217. 



